Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front element. empty() -- Return whether the queue is empty.

Example: MyQueue queue = new MyQueue(); queue.push(1); queue.push(2);
queue.peek(); // returns 1 queue.pop(); // returns 1 queue.empty(); // returns false

Notes: You must use only standard operations of a stack -- which means only push to top, peek/pop from top, size, and is empty operations are valid. Depending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as long as you use only standard operations of a stack. You may assume that all operations are valid (for example, no pop or peek operations will be called on an empty queue).

class MyQueue {
    private Stack<Integer> s1;
    private Stack<Integer> s2;

    /** Initialize your data structure here. */
    public MyQueue() {
        s1 = new Stack<>();
        s2 = new Stack<>();
    }

    /** Push element x to the back of queue. */
    public void push(int x) {
        s1.push(x);
    }

    /** Removes the element from in front of queue and returns that element. */
    public int pop() {
        peek();
        return s2.pop();
    }

    /** Get the front element. */
    public int peek() {
        if(s2.empty()) {
            while(!s1.empty()) {
                s2.push(s1.pop());
            }
        }

        return s2.peek();
    }

    /** Returns whether the queue is empty. */
    public boolean empty() {
        return(s1.empty() && s2.empty());
    }
}